Lord Stevenson, former chairman of HBOS, appearing before a parliamentary treasury committee in 2009. Photograph: PA

You had to feel a twinge of pity for Lord Stevenson, who was the chairman of HBOS when it went down the khazi in 2008. Being monstered by a bunch of MPs is one thing; to be torn apart by a ravening committee of both houses, including a former chancellor, a past head of the civil service, the new archbishop of Canterbury and, most terrifying of all, Mr Andrew Tyrie MP, a man who would insult the Queen if he thought she deserved it, must leave a man scarred forever.

And scarred he was. For over three hours he flapped his hands in every direction, like a marionette being worked by a flock of butterflies. His arms would wave, his hands chop, and at one point he could have been performing to a karaoke version of YMCA.

As the whole grisly session continued he developed a gesture which involved holding his hands together as if in prayer, while suddenly bending forwards, so he looked like Justin Welby's forerunner Thomas à Becket being hit by the first knight. It was awful.

Bad enough was the hour-long grilling from the parliamentary commission on banking standards' lawyer, Rory Phillips QC, who seemed to be far more familiar with the HBOS balance sheet than Lord Stevenson ever was. The hapless peer sometimes pleaded that it was a long time ago and his memory was fading. If he'd said that the dog had eaten his accounts, the committee would have looked less cynical.

He appeared to be saying that everyone who worked for HBOS was decent, honest and fragrant. They had been guided by knowledge, wisdom and commonsense. The committee looked astounded. Lord Turnbull, once head of the civil service, pointed out that their funding gap was greater than all other British banks put together. Nigel Lawson, father of the better known Nigella, told him he was living in cloud cuckoo land. All he had had to do was attend to the bank's culture and strategy, and on both he had failed. Then he licked his fingers seductively. (No he didn't! I made that up!)

That was before the chairman, Andrew Tyrie, got to work. Mr Tyrie resembles an Oxford don examining a student who has spent all his first year smoking pot. Had Lord Stevenson even prepared for the session? He tried to analyse why his evidence was so appalling. "I do lean towards the delusional rather than the mendacious," he said. "The markets had rumbled you."

Lord Stevenson's voice began to rise, piteously. At one point he sounded as if he were crying, though I could see no tears. Was he a fit person to head a financial institution? he was asked, and replied that he didn't want to answer. "I shall keep asking you until you do." Finally, horribly, whimperingly, his victim said: "I don't know."

Some relief, surely, from the archbishop-select. But no. His supersize cross jiggling gently on his chest, he said the figures showed the bank's capital had been wiped out, "the very definition of failure".

At one point the wretched man grovellingly confessed to having failed, but if he was shriven of his sins by the archbish, I missed it.